Develop Reference

Making PreferenceScreen not write to default SharedPreferences

I have a PreferenceScreen:
<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
<CheckBoxPreference
android:id="#+id/checkBoxHighlightWeekends"
android:key="checkBoxHighlightWeekends"
android:summary="Weekends are different"
android:title="Highlight weekends" />
<MultiSelectListPreference
android:id="#+id/multiSelectListSelectWeekends"
android:key="multiSelectListSelectWeekends"
android:dialogTitle="Select weekends"
android:entries="#array/weekends"
android:entryValues="#array/weekends_values"
android:summary="Saturday, Sunday"
android:title="Select weekends"/>
</PreferenceScreen>
I'm trying to use only the "view" part of this and not make it write to it's default SharedPreferences. When user changes the preference, I manually check the changed data and send it to a MVVM repo, when then writes to my own custom SharedPreference. I plan to use LiveData to update the settings screen when it's opened. All this hassle because I'm trying to learn the MVVM architecture and Android in general.
Inside MainPreferenceFragment:
#Override
public void onCreate(final Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
addPreferencesFromResource(R.xml.settings_main);
CheckBoxPreference checkBoxHighlightWeekends = getPreferenceManager().findPreference("checkBoxHighlightWeekends");
MultiSelectListPreference multiSelectListPreference = getPreferenceManager().findPreference("multiSelectListSelectWeekends");
checkBoxHighlightWeekends.setOnPreferenceChangeListener(changeListener);
multiSelectListPreference.setOnPreferenceChangeListener(changeListener);
}
Preference.OnPreferenceChangeListener changeListener = new Preference.OnPreferenceChangeListener() {
#Override
public boolean onPreferenceChange(Preference preference, Object o) {
// Call method in ViewModel which will save settings state to SharedPrefs
Logger.alert("Something changed! " + preference.getKey());
return true;
}
};
Any change to settings triggers the function, however the checkbox stops working - It doesn't change to the "tick" state anymore.
How can I strip out all the default click/change functionality from the PreferenceScreen and make it into a dumb view?

Preference key always return null

I have a Preference Screen in my android app which contains a call to the system settings via an inner Preference and some Switches options as below:
<PreferenceCategory
android:title="#string/preferences_activity_supervisor_settings_title">
<Preference
android:key="#+id/instrument_preference"
android:title="#string/instrument_settings"
android:summary="#string/instrument_settings">
</Preference>
<com.CustomSwitchPreference
android:key="#string/prefs_super_autosend_key"
android:title="#string/prefs_super_autosend_title"
android:summary="#string/prefs_super_autosend_summary"
android:defaultValue="false"/>
...
...
My class extends PreferenceFragment and I added the resources using addPreferencesFromResource(). It works without problems.
However, the method onPreferenceTreeClick(), when I click in the Fragment (keyID = instrument_preference) the preferences always brings me key as NULL. All other options in the preference fragment I can read the key.
The question is why and how I detect the user clicked in the first element of my preference list ?

First remove + from #+id, because every time it create a new key due to #+id, thats why you get null.
And to detect SharedPreference is changed use this simple code:
public class MyPreferences extends PreferenceActivity implements SharedPreferences.OnSharedPreferenceChangeListener {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
addPreferencesFromResource(R.xml.fw_preferences); //deprecated
PreferenceManager.getDefaultSharedPreferences(this).registerOnSharedPreferenceChangeListener(this);
}
#Override
public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
// handle the preference change here
}
}

Try removing #+id before the preference key name
It should be like
<Preference
android:key="instrument_preference"
android:title="#string/instrument_settings"
android:summary="#string/instrument_settings">
</Preference>

Adding a TextView inside a PreferenceScreen's Preference

In this preferenceScreen the user unlinks the device from his account. At the moment I just have it as Unlink device, once the user clicks it, the unlinking happens.
But I would like to add a piece text like this:
Joe Foo's Device (joefoo#gmail.com) - Unlink Device
Hoe would I do this? I also need to add the user name dynamically from settingsActivity.
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android" >
<Preference android:title="#string/pref_title_advanced_unlink" >
<TextView somehow must be in here
android:id="#id/user_name_and_email" />
<intent android:action="android.intent.action.VIEW"
android:targetPackage="com.example.tvrplayer"
android:targetClass="com.example.tvrplayer.UnlinkActivity"
android.setflags="FLAG_ACTIVITY_CLEAR_TOP"/>
</Preference>
</PreferenceScreen>

preferences.xml
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android" >
<PreferenceCategory
android:key="pref_title_advanced"
android:title="Advanced" >
<CheckBoxPreference
android:defaultValue="false"
android:key="pref_title_advanced_link"
android:title="Link Device" />
</PreferenceCategory>
</PreferenceScreen>
PrefsActivity.java
private SharedPreferences mPreferences;
private SharedPreferences.OnSharedPreferenceChangeListener mPrefListener;
private CheckBoxPreference mCheckBoxPref;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
addPreferencesFromResource(R.xml.preferences);
mCheckBoxPref = (CheckBoxPreference) getPreferenceScreen().findPreference(
"pref_title_advanced_link");
/*
* set initial summary as you desire. For example, userIdCurrent can be:
* "No Devices linked."
*/
mCheckBoxPref.setSummary(userIdCurrent);
mPrefListener = new SharedPreferences.OnSharedPreferenceChangeListener() {
public void onSharedPreferenceChanged(SharedPreferences prefs,
String key) {
if (key.equals("pref_title_advanced_link")) {
/*
* set post-click summary as you desire. For example,
* userIdPost can be:
* "Joe Foo's Device (joefoo#gmail.com)".
*/
mCheckBoxPref.setSummary(userIdPost);
}
}
};
mPreferences.registerOnSharedPreferenceChangeListener(mPrefListener);
}

Preferences have a subtitle called summary. Give your preference a key, then you can use findPreference(CharSequence key) in your PreferenceFragment to get a reference to your preference object, sort of like calling findViewById to get references to Views. Then call setSummary(int) or setSummary(CharSequence) on the preference object.
Alternatively, you could do something entirely more complex by providing a custom layout for your preference objects and/or subclass Preference and implement some custom data binding. But I think the above should do what you want.

PreferencesScreen crashes on click

I have placed this into my PreferencesActivity
PreferencesActivity:
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
addPreferencesFromResource(R.xml.preferences);
Preference preferences = findPreference("key");
preferences.setIntent(new Intent(getApplicationContext(), RegisterActivity.class));
}
preferences.xml
<PreferenceScreen
xmlns:android="http://schemas.android.com/apk/res/android">
<PreferenceCategory android:title="Preferences">
<Preference android:key="Pssword" android:title="Set SMS Notification Password"></Preference>
</PreferenceCategory>
</PreferenceScreen>
The moment i try to enter the preferences screen it crashes.

Your preference is called Pssword, not key.

You have a NullPointException because your key preference doesn't exist.
Replace your line Preference preferences = findPreference("key"); with Preference preferences = findPreference("Pssword");
This should resolve your issue.

PreferenceActivity display/edit the values of a domain object

Given this code, how do I get the values from the checkbox- and textpreference and store them in the domain object?
public class MonitorPreferences extends PreferenceActivity {
private PersistenceManager pm;
private Monitor monitor;
private boolean mActive;
private String mName;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
pm = new PersistenceManager(getApplicationContext());
addPreferencesFromResource(R.xml.monitors_pref);
fetchDomainObject();
}
private void fetchDomainObject() {
monitor = pm.fetchMonitor(getIntent().getLongExtra(SuperListActivity.EXTRA_KEY_MONITOR_ID, -1));
}
private void persistDomainObject(Monitor monitor) {
pm.persist(monitor);
}
}
<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
<PreferenceCategory android:title="General">
<CheckBoxPreference
android:key="active_chkbox"
android:title="Active"
android:defaultValue="true"
android:persistent="false"/>
<EditTextPreference
android:key="name_txt"
android:dependency="active_chkbox"
android:title="Name"
android:summary="Enter a name"
android:dialogTitle="Enter a name"
android:dialogMessage="Enter a name"
android:defaultValue="John Doe"
android:persistent="false"/>
</PreferenceCategory>
</PreferenceScreen>
Original question: Creating a normal Activity with the look and feel of a PreferenceActivity
My goal is to edit the variables of a domain object from an Activity with the look and feel of stock android preferences. What's the easiest way of accomplishing this?
Would it be possible to create a a PreferenceActivity and somehow modify it to display/edit the values of a domain object instead of the values from SharedPreferences?

Of course. Just add the code to store the values into the database and don't forget to mension android:persistent=false attribute in your preferences xml.
final CheckBoxPreference soundcb = (CheckBoxPreference) findPreference("active_chkbox");
Further you can do many things with soundcb object: read the value, set onClickListeners and so on.